1. Field of the Invention
The invention relates to a leno-heddle with two lifting heddles and one doup.
2. Prior Art
The lifting heddles known today consist of two shanks which are as a rule welded together. The two shanks of the lifting heddles suited for riderless heddle frames are welded together and on both the ends an end loop plate is welded on. The shanks of the lifting heddles are manufactured of a rolled flat steel strip and the doups are of a tempered strip steel.
Such leno-heddles are generally used up to now although some disadvantages are known which on fast running weaving machines become more and more apparent. During weaving, a dry friction between the lifting heddles and the doups will occur, which forms a metallic abrasive. This metallic abrasive can cause very unpleasant soiling on the fabric when weaving brightly dyed warp threads. Also, the wear and tear on the lifting heddles and the doups is too great resulting in poor operational characteristics and increased maintenance costs.
Since the shanks of the lifting heddles are made of rolled wire, the cross-section remains the same over their entire length. Therefore, it is not possible to increase the dimensions of parts which are exposed to greater stress and, on the other hand, to reduce parts which could be made lighter.
The lifting heddles suitable for riderless heddle frames consist of two shanks and two end loop plates which are welded onto same. Sometimes a plate is welded in between the shanks which can serve as resting point for the doup. The manufacture entails a lot of work and special steel alloys have to be used which can be processed only by means of expensive manufacturing methods.